4+3 acting strange
Thread Starter
Burning Brakes
Joined: Jul 2003
Posts: 811
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From: OH
St. Jude Donor '06-'07-'08-'09
4+3 acting strange after fluid change
I changed the fluid in 86 coupe OD unit last week. I never seen ATF that looked that bad. It was dark brown and smelled like 80/90 gear oil. I have no idea how long it had been since the fluid was changed. I've put 7000 miles on the car since I bought 18 months ago, so I decided to go ahead and change the fluid. Now the OD will disengage on its own sometimes when I reduce throttle. This is very disconcerting at highway speeds, let me tell you. Has anyone else run across this problem. I'm going to go thru the FSM in the morning to see if there is anything I can check, but I thought I'd ask the gurus here on the forum first.
Thanks
Dan
[Modified by nitrous1, 9:35 PM 8/16/2003]
Thanks
Dan
[Modified by nitrous1, 9:35 PM 8/16/2003]
Thread Starter
Burning Brakes
Joined: Jul 2003
Posts: 811
Likes: 0
From: OH
St. Jude Donor '06-'07-'08-'09
Re: 4+3 acting strange after fluid change (scorp508)
Scorp.
I filled the OD with 1.75 quarts of Mobil 1 ATF per an old post I found in the archives. I think it was something that you posted, but I can't remember for sure. I will have to look it up again. When I changed the fluid, I disconnected the lines and blew them and the cooler out with compressed air. I read about 4+3's running hot because the lines were plugged and solving the problem by cleaning out the lines. My unit used to roast you out of the car on anything other than a short trip. It generated so much heat, you did not need to turn on the heater in winter time. After I cleaned out the lines, it seems to run much cooler. I put about 100 miles on it yesterday, and it never did get hot.
Dan
[Modified by nitrous1, 11:59 AM 8/17/2003]
I filled the OD with 1.75 quarts of Mobil 1 ATF per an old post I found in the archives. I think it was something that you posted, but I can't remember for sure. I will have to look it up again. When I changed the fluid, I disconnected the lines and blew them and the cooler out with compressed air. I read about 4+3's running hot because the lines were plugged and solving the problem by cleaning out the lines. My unit used to roast you out of the car on anything other than a short trip. It generated so much heat, you did not need to turn on the heater in winter time. After I cleaned out the lines, it seems to run much cooler. I put about 100 miles on it yesterday, and it never did get hot.
Dan
[Modified by nitrous1, 11:59 AM 8/17/2003]
Team Owner
Joined: May 2002
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From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
Re: 4+3 acting strange after fluid change (nitrous1)
It sounds like you filled it right. I'm willing to bet that new fluid is contaminated with the old slime still. Change it once more pretty soon, and you'll be better off. Also, make sure that filter grommet is seated on the pickup, and that you pull the pickup all the way down to seat it in place, otherwise the pump can suck air and trip the low pressure switch, even with a full fill of atf.
The low pressure switch closes at 65 psi, and opens at 40 psi.
The low pressure switch closes at 65 psi, and opens at 40 psi.
